This invention relates to an improved combine concave structure.
Numerous types of concave structures are used in combines presently known. Conventionally these concave structures form the bottom cylindrical surface of a cylindrical housing in which a rotor rotates. The grain is compressed between the outer surface of the rotor and the interior surface of the cylindrical housing so that the grain is removed from the cob or chaff and is permitted to fall through the grate formed by the concave structure.
Present concave structures utilize a grid work of axially extending members are circumferentially extending members. In prior art concave structures, the interior surfaces of the axially extending members lie in a different arcuate surface than the interior surfaces of the circumferentially extending members. This results in the circumferential and axial members lying in two separate concentric arcuate surfaces. Consequently, a rough interior cylindrical surface is presented by this concave structure.
When present day structures are utilized, the corn shucks, or chaff from other types of grain, catch on the rough inwardly presented surface of the concave. During operation, the concave often becomes clogged, particularly at the feed end of the rotor. The result is that the farmer must clean out the concaves numerous times during operations.
Another problem encountered with present day concave structures is that a small opening is often formed adjacent the adjoining edges of the concave and the cylindrical housing thereabove. This problem is particularly noticeable adjacent the one edge of the concave which is hinged. This results in one of two phenomena occurring. Corn shucks, silks or other chaff fall through the opening caused by the juncture and fall onto the augers which are below the concave structure. This results in clogging or overworking of the augers which requires cleaning.
Therefore, a primary object of the present invention is the provision of an improved concave structure which will reduce the clogging of the concave and of the augers below the concave, particularly adjacent the intake end of the rotor cylinder.
A further object of the present invention is the minimizing of the clogging of the concave with corn stalks, corn silks, or other debris from other types of grain crops.
A further object of the present invention is the provision of an improved concave structure wherein corn shucks, corn silks, chaff, or other materials are not permitted to escape through the juncture between the concave and the remaining cylindrical housing of the combine.
A further object of the present invention is the provision of a device having a concave structure which minimizes the damage to the grain kernels during the combining process.
A further object of the present invention is the provision of a concave structure which presents a relatively smooth cylindrical surface toward the rotor within the combine cylinder.
A further object of the present invention is the provision of a device which is economical to manufacture and durable in use.